1) Field of the Invention
The present invention concerns a process for producing and completely assembling a medical operations syringe, such as a syringe intended to contain a medical liquid to be injected or an organic liquid taken from organisms.
2) Description of Related Art
Notoriously, the syringes traditionally used to perform medical operations, such as injections or samples, include a usually cylindrical hollow body, made of plastic material, and a thrust piston, partly contained into the hollow body within which is made sliding by actuating means, (i.e., operator's hand), in order to perform medical interventions.
The thrust piston is provided at a first end with a handle head, accessible to the operator, and at a second end with a seal plunger, usually made of rubber, placed inside the hollow body and suited to come into contact with the liquid to be injected or taken during the medical operations.
In turn, the hollow body presents a main inlet at a first end, through which the thrust piston is inserted into the hollow body itself, and at a second end of a narrowing beak or neck, a hollow needle is engaged through which the injected liquid passes.
Currently, syringes for medical operations are mainly produced through a process of injection moulding, whereby the nominal essential components mentioned above, namely hollow body, thrust piston, seal plunger and needle, are obtained separately in operative steps and subsequently assembled by the operator.
This implies two main sets of drawbacks, without any doubt of not slight importance for the known technique of the field.
Firstly, in fact, the syringe assembly operations occur inevitably with some manipulation of the aforesaid components, with the obvious and consequent risk of contamination, due to exposure or contact with external agents, although operations themselves are done with extreme care and caution in an environment with a high degree of microbiological cleanliness.
This problematic issue appears in all its evidence and critical state when analyzing single-dose syringes pre-filled with medical liquid: in this case, the hollow body, thrust piston, seal plunger and needle with its needle-carrier are transferred and delivered to the producer of the drug who, after having filled the hollow body with the liquid, provides to assemble together the pieces just mentioned in a controlled atmosphere environment (so-called “white room”) in order to avoid contaminating the liquid.
Although strict procedural protocols are provided, such an approach does not completely reduce the risk of contamination of both of the components and the medical liquid: not by chance, however, it is usually required the application of an additional plastic envelope to package the syringe just assembled in order to assure the highest possible aseptic conditions and, therefore, of safety in the subsequent use thereof.
Secondly, the production technology and resulting assembling system of a syringe currently used require fairly long implementation times, which, combined also with the sophisticated equipments used to ensure the maximum aseptic conditions and, therefore, safe conditions of use, determine a certain economically expensive situation which reflects in market prices less competitive than expected.